38 NEW ZEALAND PLANTS. 



mako) has distinctly pleasing rosy-coloured flowers. The hinau 

 (Elaeocarpus dentatus) has numerous white drooping flowers. The 

 large -flowered clematis (Clematis indivisa, puawhananga) is esteemed 

 by all, and its snowy blossoms are frequently torn from their forest 

 home only to wither. 



THE FERTILISATION OF THE FLOWERS. 



The methods by which flowers are fertilised are of high interest, 

 and for the past half-century have received much attention. Space 

 permits only a brief mention here. 



The majority of flowering-plants have two special organs for pur- 

 poses of fertilisation, the stamen and the pistil. The former produces a 

 yellow " dust," the pollen ; the latter contains within a little chamber* 

 one or more little roundish or oval bodies, the ovules. Each ovule 

 contains in its interior what may be called an " egg." If the pollen 

 falls upon that part of the pistil termed the ' stigma ' at the right 

 time, a union will eventually take place between some of the essential 

 part of the pollen and the egg. This will lead to the formation of 

 an embryonic plant within the ovule, which, when the embryo i.e., 

 the little plant with seed-leaves and rudimentary root and stem is 

 fully developed, is termed the seed. 



In some instances the stamens and pistil are close together on the 

 same flower, and pollen and stigma are ready the one for the other 

 at the same time, in which case the flower can fertilise itself. But in 

 a considerable number of instances self-fertilisation is impossible, 

 and the pollen of one flower must be applied to the stigma of 

 another. Such cross-fertilisation, as it is called, has been proved to be 

 beneficial for many plants. A large percentage of New Zealand trees 

 and shrubs have the pollen-bearing flower on the one plant and the 

 ovule-bearing on another. Others again are so constructed that the 

 pollen is ripe before the stigma of the same flower is ready to receive 

 it. or the stigma may in other species be developed before the pollen. 

 In all these cases cross-fertilisation is alone possible. This may take 

 place in two ways : either the wind may carry the pollen from one 

 flower to another, as in the genus Coprosnm and in many other cases, 



Mil the pint's the ovules ure not enclosed in a chamber, and there is no 

 stigma. The pollen is conveyed by the wind and deposited on the ovules 

 directly. 



